This invention relates to an apparatus for automatically imprinting markings on the so-called bombs, or steel or like metal cylinders for compressed gases, among other metal-made cylindrical articles. More specifically, the invention deals with such marking apparatus capable of imprinting several lines of characters in a predetermined position on each gas cylinder or the like.
As is wll known, steel cylinders are widely used as containers for compressed gases such as those of oxygen, chlorine, hydrogen, and carbon dioxide. Such steel cylinders are required to be clearly engraved or imprinted with markings giving such information as the contents, date of production, serial number, and name of the manufacturer. This marking operation has heretofore been the handiwork of highly skilled artizans, performed at the expense of substantial time and labor because the information must be impressed on rounded surfaces of hard material. Moreover, as an inevitable result of manual operation, the characters impressed tend to be of irregular arrangement and uneven depth.